We know that the weight G is a force calculated as:
G [N] = m [kg] · g [m/s²], where m is mass in kilograms and g is the gravitational acceleration, equal to 9.8 m/s².
Now we calculate the weight of the weightlifter:
Gwl = 132 · 9.8 = 1293.6 N
The normal force applied to the weightlifter from the floor is the sum between the weight of the weightlifter and the weight of the dumbbell:
Gn = Gwl + Gdb = 1293.6 + 450 = 1743.6 N